Many wireless communication apparatuses employ intermittent operation. The intermittent operation stops the apparatuses when input-output signals do not exist. The intermittent operation sets the apparatuses to a standby mode to reduce their consumption current. An intermittent reception permits an RF unit or a microcomputer to operate during the intermittent reception. The intermittent reception sets the microcomputer to a sleep mode during signal waiting.
The wireless communication apparatuses for keyless entry have a standby period longer than an operating period. The wireless communication apparatuses for keyless entry have a data-transfer amount smaller than that of a common data-communication system. Wireless signals are transmitted from mobile phones for keyless entry. Received signals are not necessarily detected during an intermittent reception period. For this reason, the intermittent operation makes it difficult to shorten an intermittent reception period and reduce consumption current.